Authorities suspect Rodriguez was illegally intoxicated Monday night when he struck the back of a red Kawasaki motorcycle as traffic slowed on Loop 1604 West.

Rodriguez's blue Dodge Stratus came to a stop in a grassy shoulder with Van Volkenburg, who wore a helmet, pinned beneath, police said. Witnesses reportedly stopped to help and were able to lift the car off of the motorcyclist, who is from Helotes.